A pure devotee can see the presence of the Supreme Personality of Godhead in everything materially manifested. He is present there only as a reflection, but a pure devotee can realize that in the darkness of material illusion the only light is the Supreme Lord, who is its support. It is confirmed in Bhagavad-gita that the background of the material manifestation is Lord Krsna. And, as confirmed in the Brahma-samhita, Krsna is the cause of all causes. In the Brahma-samhita it is stated that the Supreme Lord, by His partial or plenary expansion, is present not only within this universe and each and every universe, but in every atom, although He is one without a second. The word advayam, without a second, which is used in this verse, indicates that although the Supreme Personality of Godhead is represented in everything, including the atoms, He is not divided. His presence in everything is explained in the next verse.